1. Field of the Invention
This invention relates to a pipe connecting device to connect mutual ends of pipes and thus create a flow of liquids for refrigeration cycle in an automotive air conditioning device.
2. Description of the Related Art
Among devices for connecting refrigerant pipe for refrigeration cycle in automotive air conditioners, there is, for example, Japanese Patent Application Laid-Open No. Hei 4-266521. That invention has a structure in which connecting flanges are attached to the male and female side refrigerant pipe, and the connecting flanges are connected to thus connect the refrigerant pipe on the male side and the refrigerant pipe on the female side. FIG. 14 and FIG. 15 show the structure of the connecting flanges.
FIG. 14 and FIG. 15 show a connecting flange 3 of the refrigerant pipes 1 and 2 on the male side. This connecting flange 3 is composed of two dividing flanges 4 and 5. The dividing surfaces of dividing flanges 4 and 5 include the concave grooves 4a, 4b and 5a, 5b. Dividing flange 4 includes hook-shaped retainers 4c and 4c on both sides. Dividing flanges 4 and 5 are made of resin mold and include the nuts 6 and 7 which are inserted at the time of molding.
As FIG. 15 shows, in order to attach the connecting flange 3 (i.e. the dividing flanges 4 and 5) to the refrigerant pipes 1 and 2, the dividing flanges 4 and 5 are slid with the concave grooves 4a, 4b and 5a, 5b fit into the refrigerant pipes 1 and 2, thus fitting both ends of dividing flange 5 into the retainers 4c, 4c of dividing flange 4. A small screw 8 passed through dividing flange 5 is screwed to dividing flange 4. Thus, as shown in FIG. 14, the connecting flange 3 is attached to refrigerant pipes 1 and 2.
The connecting flange of the refrigerant pipe on the female side has the same structure as the connecting flange 3, although it differs in not including the nuts 6 and 7. Instead there is a hole for insertion of a bolt.
In order to connect the refrigerant pipe on the male and female sides with such connecting flanges, the ends of the refrigerant pipes 1 and 2 on the male side are inserted in the female pipe, after which the connecting flange 3 on the male side and the connecting flange on the female side are joined together. Then the bolts passed through the holes on the two dividing flanges on the female side are screwed to the nuts 6 and 7 of the dividing flanges 4 and 5 of the refrigerant pipes 1 and 2 on the male side in order to connect the connecting flange 3 on the male side and the connecting flange on the female side. As a result, the refrigerant pipe on the female side is connected with the refrigerant pipes 1 and 2 on the male side.
However, the existing pipe connecting device described above has a structure in which the connecting flange 3 on the male side and the connecting flange not shown in the figure on the female side are connected by screwing two bolts to the two nuts 6 and 7. The result is a large number of parts, thus reducing the efficiency of connection operations. Also, because the nuts 6 and 7 are formed together with the dividing flanges 4 and 5 by an insert mold, the molding costs for the dividing flanges 4 and 5 are high.